if you can't find it, it could be because Larry had it shut down.
he's literally threatened to take action against at least one online DiMarzio-themed resource for people discussing the engineering of DiMarzio products as well as posting photos of a DiMarzio product someone bought and disassembled.
let that sink in. a place started and operated by a fan as a place for other fans to gather, not unlike this forum. DiMarzio didn't start it and isn't funding it or even supporting it. and Larry threatened to take action because someone bought a product, which makes it their property, and posted a photo of the bottom with the baseplate removed... which is something that anyone can figure out from the publicly available patent info... as in, it's no big secret.
anyway, good luck on finding the info you're looking for.